The 85-year-old stepped down last month, saying he was no longer strong enough to lead the Church, which is beset by problems ranging from a worldwide scandal over child sex abuse to allegations of corruption at the Vatican Bank.

The cardinals will vote four times daily until a single candidate garners enough support – at which point the smoke coming from the Sistine Chapel chimney will be white.

After celebrating Mass this morning, they returned to the Sistine Chapel to resume voting.

They can vote twice in the morning. If those ballots are inconclusive, black smoke will once again rise from the chimney and the election will resume after lunch.

Voting takes place in silence, with no formal debate, until a decision is reached. If that does not happen after three days, there may be a pause for prayer and informal discussion for a maximum of one day.